Raw milk safety and avian influenza virus: vaccination

Raw milk is coming under new scrutiny as bird flu continues to infect dairy herds.

very Pathogenic Deadly strain of influenza in birds At least 58 herds Ten dairy cows and at least two humans have been infected in nine states after the virus was found in samples of unpasteurized milk. USDA Testing.

But despite federal advice against drinking raw milk, it is still sold and easily available in many places across the country.

In Texas, where avian influenza was first detected in cattle and where the infection has continued to spread since then, Found in groups of 12 or moreAfter a reporter purchased raw milk on May 8 and submitted it for testing, NPR discovered that some farms that sell unpasteurized raw milk to the public are refusing to have their supplies tested.

A USDA-certified laboratory authorized to test for the H5N1 avian influenza virus in milk called the farm seeking permission to test the milk, but the farmer did not give permission, and so they also refused to test for avian influenza in the milk.

“[The farms] “The veterinary industry knows how it will affect their business if they don't have negative tests,” said Brandon Dominguez, director of veterinary services at the Texas A&M Veterinary Diagnostic Laboratory in College Station, Tex. “They've asked us not to do the tests.”

After NPR report The USDA confirmed that it did not require farms' permission to test milk samples for avian flu, but Amy Swinford, director of the Texas A&M lab, added that another reason the lab was unable to conduct tests was because reporters did not provide facility identification numbers for each farm. These numbers are not publicly available. The reporters included each farm's license number when submitting samples for testing.

Laboratories and farms refused to test raw milk samples because Scientists have criticised The federal government has been criticized for being slow to gather and report information about the virus. Extensive testing There isn't enough information for dairy workers to know how many people are infected, dairy farms aren't required to test their herds if they don't move cows between states, and there is no clear testing data to back up federal warnings that bird flu is a potential threat to the raw milk people drink.

Supporters and critics of unpasteurized milk clash

In the absence of evidence, both sides in the raw milk debate are reinforcing traditional views.

Public health officials and academics say the risks are now elevated and precautions need to be taken until the scope of avian influenza in dairy cows and how it spreads between animals and humans is better understood.

“Pasteurization is effective at inactivating viruses,” Don Prater, director of the FDA's Center for Food Safety and Applied Nutrition, said at a May 1 press conference.[We] “We strongly advise against consuming raw milk (milk that has not been pasteurised) and advise industry not to manufacture or sell raw milk or raw milk products made from milk from cows showing symptoms of illness, including those infected with the avian influenza virus,” Prater said.

Raw milk advocates argue the theoretical risks have been overstated and that this is the latest chapter in a long and contentious battle with the federal government, which banned interstate sales of raw milk in the 1980s. “The FDA will use any excuse they can find to attack us,” said David G. Schneider, a California raw milk dairy farmer. Raw Milk Research Institutean advocacy group.

Raw milk is sold but is not recommended

Raw milk is not hard to come by in Texas. You can pick it up at a fitness center in Austin, or Dozens of raw milk dairy farms They're dotted across the state, where you can put some money into a coffer and receive a gallon of cold milk straight from the cow — milk that's never been heated to a temperature that would kill any bacteria or microorganisms that might be living in it.

Cheryl Masraum wasn't worried about bird flu because she buys her raw milk from Strike Jersey Farms in Schulenburg, Texas, between Houston and San Antonio.

“We were watching it closely, but it didn't seem like a threat here,” Masraum said, noting that cow infections were reported in northwest Texas, near the New Mexico border. “Raw milk is generally of much better quality and I think it tastes better.”

Masraum is part of a small but dedicated group of American raw milk consumers: About 1.6 percent of U.S. adults regularly drink milk that hasn't been pasteurized to kill bacteria, according to the study. Food and Drug Administration investigation.

Now, due to an outbreak of avian influenza in dairy cows, federal health officials are again warning people not to drink raw milk.

Public health officials have long Drinking raw milk is not recommendedThis is because milk can harbor pathogens, which are killed or inactivated by briefly heating the milk through a process called pasteurization.

Still, the risk of catching avian flu from raw milk is largely theoretical: “There aren't many studies showing infectivity associated with this virus and raw dairy products,” the FDA's Prater said at a press conference.

How much avian flu virus is in milk?

The FDA found fragments of the avian flu virus in 20 percent of pasteurized grocery store samples it collected and tested. According to a recent surveyFDA tests showed that these viral fragments were not capable of causing infection.

According to the federal government, the virus appears to be spreading among herds through the movement of infected cattle. The current hypothesis is that H5N1 was transmitted from birds to dairy cows in Texas in late 2023. Then, “the transportation of cattle from Texas to a number of other states basically created problems in those states,” Agriculture Secretary Tom Vilsack told reporters on May 10. Vilsack said the USDA's current strategy, which requires cattle to test negative before being moved across state lines, is aimed at “containing the spread and ultimately eradicating the virus in certain herds.”

Raw milk advocates argue that farms are small and herds are relatively isolated. Buy legally “I have never had contact with cattle produced in other states. I don't buy cattle from other states. So why? [our cows] “The cows and the milk are both good,” said McAfee of California. Samples from California The test came back positive.

Virologists counter that there is insufficient surveillance to determine the limits of the epidemic: “We don't know if we have the information because we're not testing systematically,” they say.Dr. Helen Chu“It's a very rapidly mutating virus that jumps from humans to birds to pigs to cows and all these different species,” said the infectious disease expert at the University of Washington in Seattle. Avian flu is carried by wild waterfowl and migratory birds, which “fly around and dump their waste into farm feed,” which is why we know it's spread so quickly. [enough] “To make sure we know this is a unique occurrence,” Chu said.

One way to determine whether raw milk intended for human consumption contains the H5N1 virus is to test it. Lea StaritaShe runs a genomic testing lab at the University of Washington and tested dozens of samples of raw and pasteurized milk purchased from local farmers markets and grocery stores. While the raw milk samples came back negative, she found what appeared to be fragments of the virus in about 5% of the samples.

But raw milk isn't routinely tested for avian influenza, and farms have refused requests to test it, according to NPR. others i got you.

“They're frankly scared of what's going to happen to their farms and their families. This isn't just a public health issue. It's an economic issue and, frankly, a survival issue,” said Swinford, director of the Texas A&M lab, which declined to test the milk submitted by NPR for analysis.

On May 21, a Texas A&M lab official confirmed to NPR that the lab could ship samples to other labs and that shipping was a service the lab offers to its clients. But on May 22, Swinford called a reporter and said the lab would not allow that to happen for the raw milk NPR had purchased and submitted for avian flu testing.

“I'm not going to promote that … because I told these dairies not to be inspected,” Swinford said.

Can avian influenza be transmitted to humans by consuming raw milk?

The federal government's warning against consuming raw milk is based on known risks. Responsible for more than 2,500 food poisonings Over the past 20 years, Campylobacter and CryptosporidiumHowever, it is unclear whether unpasteurized milk can transmit avian flu to humans.

Farm cats that drank unpasteurized milk from infected cows became severely ill, with some cats going blind, suffering severe neurological effects and dying after drinking it, according to a recent journal report. Emerging infectious diseasesAccording to a May 24 report, mice fed infected, unpasteurized milk from cows in New Mexico quickly became ill and had large amounts of the virus in their respiratory tracts. New England Journal of MedicineCo-authored with Swinford of Texas A&M University.

So far, there have been no confirmed cases of humans contracting bird flu from drinking raw milk. Two dairy workers in Texas and Michigan have contracted bird flu after working closely with infected cows. In both cases, the workers developed eye infections but later recovered.

On May 1, the CDC announced that health officials had monitored more than 100 workers and found no cases of avian flu. But a Texas veterinarian told the publication: Cattle Veterinarian How many sick farmworkers are not being tested?

From a consumer standpoint, McAfee and other raw milk advocates see the low number of cases as reassuring: If no one has yet caught avian flu from drinking raw milk, it may never happen in the first place.

But public health officials maintain that avian influenza in dairy cows remains a new and evolving situation. “There are many unanswered questions and much more to learn,” they said. Lori Freeman“Until we know more about the spread of this particular pathogen to animals and humans, we need to take ample precautions,” said the president of the National Association of County and City Health Officials.

Milk farmers say they're watching developments closely and working to ensure their cows are healthy and their milk is safe. And the controversy isn't likely to sway their loyal customers. “The people who follow us would run away if the FDA said it was bad,” said one source. [towards] “In my opinion, when it comes to raw milk here in California, we don't need to make a big fuss about zero,” McAfee said.